Re: [PATCH] ssb:: use put_device() if device_register fail

From: arvindY
Date: Wed Mar 07 2018 - 12:16:28 EST




On Wednesday 07 March 2018 10:17 PM, Michael Büsch wrote:
On Wed, 7 Mar 2018 15:31:30 +0530
Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> wrote:

if device_register() returned an error! Always use put_device()
to give up the reference initialized.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
---
drivers/ssb/main.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
index 65420a9..c4449e0 100644
--- a/drivers/ssb/main.c
+++ b/drivers/ssb/main.c
@@ -521,6 +521,7 @@ static int ssb_devices_register(struct ssb_bus *bus)
ssb_err("Could not register %s\n", dev_name(dev));
/* Set dev to NULL to not unregister
* dev on error unwinding. */
+ put_device(dev);
sdev->dev = NULL;
kfree(devwrap);
goto error;

I don't think this is correct.
The dev structure is allocated as part of devwrap, which is freed here.

Why do you think we need put_device here?

Yes this patch is not correct, We must not use kfree() after you called device_register() (even
if it was not successful!) -- see the comment for device_register().
I will delete kfree() and send updated patch.

~arvind